Have you ever felt a panic attack in real life?
Vidunenahawula Website (National Institute of Fundamental Studies)
In movies or in real life you may have seen when someone has a panic attack he would breathe quickly. Then another person would give him a paper bag to breathe in. When breathing into the paper bag he would feel calm and the panic attack would sometimes fade away. Explain how breathing rapidly could cause dizziness.
Sometimes when a person has panic attack that person would breathe rapidly. The condition which you breathe rapidly is known as hyperventilation. When a person hyperventilate he/she would breathe faster and deeper than normal. This causes the oxygen level in the blood to rise while the carbon dioxide level in your blood decreases. When the level of carbon dioxide in the blood decreases the arteries that carry blood to your brain constricts. This limits the supply of blood to your brain. This causes dizziness and light headedness.